Photosensitive polymer-containing systems with increased shelf-lives

Abstract

A photosensitive polymer-containing system containing: (a) an energy sensitive polymer having a linear hydrocarbyl backbone and pendant peptide groups with free-radically polymerizable functionality attached thereto; (b) a vinyl-halomethyl-s-triazine capable of free-radical generation upon excitation with electromagnetic radiation having a wavelength of from about 330 to 500 nm; (c) an organic acid having a pKa of from about 1.8 to 5.5; (d) a leuco dye; and (e) a binder. A colorant may optionally be added. The photosensitive systems exhibit an increased shelf-life and excellent photosensitivity.

What is claimed is: 
     
       1. A photosensitive polymer-containing system comprising: (a) an energy sensitive polymer having the formula: ##STR10##  wherein: R 1  independently is hydrogen or methyl;   2  is given by: ##STR11##  wherein: n is 0 or 1; R 5 , R 6 , R 7 , and R 8  are independently an alkyl group having 1 to 12 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms, an aryl or aralkyl group having 6 to 12 carbon atoms or at least one of the pairs R 5  and R 6 , and R 7  and R 8 , taken together with the carbon to which it is joined forms a 5- or 6-membered carbocyclic ring, or any of R 5 , R 6 , R 7  and R 8  may be H when n is 1;   W is --NH--, NR 20 , --S-- or --O--, wherein R 20  can be alkyl of 1 to 12 carbon atoms; and   Z represents ##STR12##  wherein R 5 , R 6 , R 7 , R 8 , and n are as previously defined;   R 3  is a polymerizable, ethylenically unsaturated group selected from;   (a) ##STR13##  in which R 9  can be an alkylene group having 1 to 12 carbon atoms, an arylene group having 6 to 10 carbon atoms, an oxyalkylene group or a poly(oxyalkylene) in which said alkylene group has 2 to 4 carbon atoms and the number of oxygen atoms is a positive integer less than or equal to four, R 10  is hydrogen, cyano, a carboxyl group, or a --C(═O)NH 2  group; and R 11  is hydrogen, an alkyl group having 1 to 12 carbon atoms, or a phenyl group or naphthyl group; or   (b) -R 9  -W-T in which R 9  is as defined as in (a), W is as previously defined, and T is an ethylenically unsaturated group selected from the group consisting of: acryloyl, methacryloyl, cinnamoyl, maleoyl, fumaroyl, itaconoyl, and crotonoyl; and a, b, c, and d independently are integers, wherein a and b are at least 1, and the sum of a+b+c+d is sufficient to provide a polymer having a number average molecular weight in the range of 2,000 to 1,000,000;   G is given by -R 9  -N+R 12  R 13  R 14  X-, wherein R 9  is as previously defined and wherein R 12  -R 14  are independently an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms, an aryl or aralkyl group having 6 to 12 carbon atoms or any two or all three of R 12  -R 14  taken together with the nitrogen to which they are joined can form a 5- to 8-membered heterocyclic ring, and X -   represents any non-interfering anion including anions located elsewhere on the polymeric backbone or side chains;     R represents an aryl group having from 6 to 30 carbon atoms, cyano, --CO 2  H, a carboalkoxy group having from 2 to 40 carbon atoms, or a mono- or dialkylcarbamoyl group having from 2 to 40 carbon atoms; and   R 4  represents hydrogen, or a solubilizing cation or -E-A wherein E represents an organic divalent connecting group having up to a total of about 18 C, N, S, and nonperoxidic atoms, and A is an acid selected from carboxylic acids, sulfonic acids, phosphonic acids and salts thereof;     (b) a vinyl-halomethyl-s-triazine capable of free-radical generation upon excitation with electromagnetic radiation having a wavelength of from about 330-500 nm;   (c) an organic carboxylic acid having a pKa of from about 1.8 to 5.5;   (d) a leuco dye; and   (e) a binder.   
     
     
       2. The photosensitive system according to claim 1 wherein R 1  is H, and R 5  and R 6  are methyl, and n is 0. 
     
     
       3. The photosensitive system according to claim 1 wherein said energy sensitive polymer has a homopolymeric backbone. 
     
     
       4. The photosensitive system according to claim 1 wherein said enery sensitive polymer has a copolymeric backbone. 
     
     
       5. The photosensitive system according to claim 1 wherein the A group of R 4  is an alkali metal or a tetra-substituted ammonium salt of a carboxyl, sulfo, or phospho group. 
     
     
       6. The photosensitive system according to claim 1 wherein the A group of R 4  is PO 3  H 2 , SO 3  H, or CO 2  H. 
     
     
       7. The photosensitive system according to claim 1 wherein R is --COOH. 
     
     
       8. The photosensitive system according to claim 1 wherein the energy sensitive polymer is derived from an alkenylzalactone monomer. 
     
     
       9. The photosensitive system according to claim 1 wherein the energy sensitive polymer is derived from an alkenylazlactone monomer and at least one additional free-radically polymerizable comonomer. 
     
     
       10. The photosensitive system according to claim 9 wherein said comonomer is a diacid. 
     
     
       11. The photosensitive system according to claim 9 wherein said alkenylazlactone is present in said energy sensitive polymer in the range of 10 to 100 weight percent and said at least one comonomer is present in said energy sensitive polymer in the range of more than 0 to 90 weight percent. 
     
     
       12. The photosensitive system according to claim 1 wherein said energy sensitive polymer has a number average molecular weight in the range of 2,000 to 1,000,000. 
     
     
       13. The photosensitive system according to claim 1 wherein said triazine has the following formula: ##STR14## wherein: Q is bromine or chlorine, P is --CO 3 , --NH 2 , --NHR, --NR 2  or --OR where R is phenyl or lower alkyl, n is an integer from 1 to 3 and W is an optionally substituted phenyl, pyrryl, benzopyrl, oxazoyl, benzoxazoyl, benzthiazoyl or ##STR15## where Z is oxygen or sulfur and R 1  is hydrogen, a lower alkyl or a phenyl group. 
     
     
       14. The photosensitive system according to claim 13 wherein Q is --Cl and P is --CCl 3 . 
     
     
       15. The photosensitive system according to claim 1 wherein said organic acid has a pKa of from about 2.0 to 5.0. 
     
     
       16. The photosensitive system according to claim 1 wherein said organic acid has a pKa of from about 2.5 to 3.5. 
     
     
       17. The photosensitive system according to claim 1 wherein said acid is o-phthalic acid. 
     
     
       18. The photosensitive system according to claim 1 wherein said leuco dye is a triaryl methane leuco compound. 
     
     
       19. The photosensitive system according to claim 18 wherein said leuco dye has the following structure: ##STR16## 
     
     
       20. The photosenstive system according to claim 1 further comprising colorant. 
     
     
       21. A substrate comprising the dried, coated photosensitive polymer-containing system of claim 1. 
     
     
       22. A substrate comprising the dried, coated photosensitive polymer-containing system of claim 13. 
     
     
       23. A substrate comprising the dried coated photosensitive polymer containing system of claim 15. 
     
     
       24. A substrate comprising the dried, coated photosensitive polymer containing system of claim 16. 
     
     
       25. A substrate comprising the dried, coated photosensitive polymer containing system of claim 17.